2 Separate DB

Hi experts

am facing a issue with CR

my vendor has implemented SAP (Standard) and Add on as 2 separate DB

lets assume 1 as Standard and 2 as Add on

my issue is with Crystal report

am not an expert in SQL query, so i use to drag and link table directly from Crystal reports

when i create a CR based on Add on Database and try to link or upload in Sap Standard system, its not functioning

pls suggest me how to solve the issue

Regards